Book/Report

FZJ-2018-03383

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Die Bereitstellung computerunterstützter Methoden zur Analyse der Strahlungssituation an Teilchenbeschleunigern und deren exemplarische Anwendung auf das Cooler-Synchrotron Cosy

Moll, J. (Corresponding author)FZJ*

1991
Forschungszentrum Jülich GmbH Zentralbibliothek Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18848

Report No.: Juel-2435

Abstract: In this thesis the applicability of modern particle transport programs for the radiation protection of the new cooler synchrotron COSY has been investigated. The technical and operational characteristics of accelerator facilities (individual geometry, extreme anisotropie) as well as the missing knowledge of high energy cross section data often considerably reduce the usage and reliability of conventional, semiempirical calculations. On the other hand Monte Carlo codes as the program system HERMES offer a large flexibility in geometry simulation and a wide spread applicability up to the GeV energy region because of its implemented physical models. These codes are very suitable for detailed analysis of radiation sources within the accelerator (targets, magnets and other installations) and for dose rate estimationsbehind radiation shields. Detailed calculations of double differentional flux spectra and surface dose rate distributions for n, p, $\pi^{+}$, $\pi^{-}$, $\mu^{+}$, $\mu^{-}$ and $\gamma$ at a cylindrical standard target for different materials (iron, copper and lead) were done for 2.5 GeV protons incident. The results are in good agreement with comparitiv Moyer calculations. In case of deep penetration problems it turns out, that the CPU-time requirement of the Monte Carlo codes increases rapidely. Therefore the Monte Carlo codes were coupled with a one-dimentional S$_{n}$ transport code to treat deep penetration problems in a reasonable computer CPU-time. For this purpose a new high energy neutron-$\gamma$ transport library was evaluated taking into account the upper energy limit of COSY with 2.8GeV. The needed cross sections have been calculated by using the physical models of one of the HERMES-codes. Several Fortran-routines were developed to get an automatically procedure, which is used to evaluate the results and determine Legendre polynominals of order P3, which had to be inserted as coefficients into the library. About 33000 new Legendre coefficients with 9 energy groups between 0.8 GeV and 2.8 GeV were included in an existing library calledLAHI, which is now extended beyond 0.8 GeV. Special emphasis was laid on consistency checks and comparitive calculations to confirm the physical quality of the new cross section data. The coupling procedure between the programs has been automated by means of several Fortran-routines, which does transformation, formalisation and formatting of the flux-data. A systematic investigation about the shape and location of the coupling surface led to fundamental statements. A lot of applications concerning the COSY-accelerator have been examined and discussed regarding shielding requirements and the philosophy of radiation protection measurement technique. The present results and calculational procedures based on state-of-the-art computer codes and models allow a much better estimation of the shielding and radiation protection requirements around accelerators, demonstrated at the COSY facility. Furthermore it is possible to expand the classical semiempirical methods used in radiation safety to a complete radiation protection procedure. With the flexible computer code system used there is the advantageto determine and evaluate a wide range data bank to design engineering program tools, which can be used on small computers, solving radiation protection problems of accelerator facilities.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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